/*
  * Copyright (c) 2003 Michael Niedermayer
  * Copyright (c) 2012 Jeremy Tran
  *
  * This file is part of FFmpeg.
  *

  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.

  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.

  *

  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  */
 
 /**
  * @file
  * Apply a hue/saturation filter to the input video
  * Ported from MPlayer libmpcodecs/vf_hue.c.
  */
 

 #include <float.h>

 #include "libavutil/eval.h"

 #include "libavutil/imgutils.h"

 #include "libavutil/opt.h"

 #include "libavutil/pixdesc.h"
 
 #include "avfilter.h"
 #include "formats.h"
 #include "internal.h"
 #include "video.h"
 

 #define SAT_MIN_VAL -10
 #define SAT_MAX_VAL 10
 
 static const char *const var_names[] = {
     "n",   // frame count
     "pts", // presentation timestamp expressed in AV_TIME_BASE units
     "r",   // frame rate
     "t",   // timestamp expressed in seconds
     "tb",  // timebase
     NULL
 };
 
 enum var_name {
     VAR_N,
     VAR_PTS,
     VAR_R,
     VAR_T,
     VAR_TB,
     VAR_NB
 };
 

 typedef struct HueContext {

     const    AVClass *class;
     float    hue_deg; /* hue expressed in degrees */
     float    hue; /* hue expressed in radians */

     char     *hue_deg_expr;
     char     *hue_expr;
     AVExpr   *hue_deg_pexpr;
     AVExpr   *hue_pexpr;

     float    saturation;

     char     *saturation_expr;
     AVExpr   *saturation_pexpr;

     float    brightness;
     char     *brightness_expr;
     AVExpr   *brightness_pexpr;

     int      hsub;
     int      vsub;

     int is_first;

     int32_t hue_sin;
     int32_t hue_cos;

     double   var_values[VAR_NB];

     uint8_t  lut_l[256];

     uint8_t  lut_u[256][256];
     uint8_t  lut_v[256][256];

 } HueContext;
 

 #define OFFSET(x) offsetof(HueContext, x)

 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM

 static const AVOption hue_options[] = {

     { "h", "set the hue angle degrees expression", OFFSET(hue_deg_expr), AV_OPT_TYPE_STRING,
       { .str = NULL }, .flags = FLAGS },
     { "s", "set the saturation expression", OFFSET(saturation_expr), AV_OPT_TYPE_STRING,

       { .str = "1" }, .flags = FLAGS },
     { "H", "set the hue angle radians expression", OFFSET(hue_expr), AV_OPT_TYPE_STRING,

       { .str = NULL }, .flags = FLAGS },

     { "b", "set the brightness expression", OFFSET(brightness_expr), AV_OPT_TYPE_STRING,
       { .str = "0" }, .flags = FLAGS },

     { NULL }
 };
 
 AVFILTER_DEFINE_CLASS(hue);
 

 static inline void compute_sin_and_cos(HueContext *hue)
 {
     /*
      * Scale the value to the norm of the resulting (U,V) vector, that is
      * the saturation.

      * This will be useful in the apply_lut function.

      */

     hue->hue_sin = lrint(sin(hue->hue) * (1 << 16) * hue->saturation);
     hue->hue_cos = lrint(cos(hue->hue) * (1 << 16) * hue->saturation);

 }
 

 static inline void create_luma_lut(HueContext *h)
 {
     const float b = h->brightness;
     int i;
 
     for (i = 0; i < 256; i++) {
         h->lut_l[i] = av_clip_uint8(i + b * 25.5);
     }
 }
 

 static inline void create_chrominance_lut(HueContext *h, const int32_t c,
                                           const int32_t s)
 {
     int32_t i, j, u, v, new_u, new_v;
 
     /*
      * If we consider U and V as the components of a 2D vector then its angle
      * is the hue and the norm is the saturation
      */
     for (i = 0; i < 256; i++) {
         for (j = 0; j < 256; j++) {
             /* Normalize the components from range [16;140] to [-112;112] */
             u = i - 128;
             v = j - 128;
             /*
              * Apply the rotation of the vector : (c * u) - (s * v)
              *                                    (s * u) + (c * v)
              * De-normalize the components (without forgetting to scale 128
              * by << 16)
              * Finally scale back the result by >> 16
              */
             new_u = ((c * u) - (s * v) + (1 << 15) + (128 << 16)) >> 16;
             new_v = ((s * u) + (c * v) + (1 << 15) + (128 << 16)) >> 16;
 
             /* Prevent a potential overflow */

             h->lut_u[i][j] = av_clip_uint8(new_u);
             h->lut_v[i][j] = av_clip_uint8(new_v);

         }
     }
 }
 

 static int set_expr(AVExpr **pexpr_ptr, char **expr_ptr,
                     const char *expr, const char *option, void *log_ctx)

 {

     int ret;

     AVExpr *new_pexpr;
     char *new_expr;

     new_expr = av_strdup(expr);
     if (!new_expr)
         return AVERROR(ENOMEM);
     ret = av_expr_parse(&new_pexpr, expr, var_names,

                         NULL, NULL, NULL, NULL, 0, log_ctx);
     if (ret < 0) {
         av_log(log_ctx, AV_LOG_ERROR,
                "Error when evaluating the expression '%s' for %s\n",
                expr, option);

         av_free(new_expr);

         return ret;

     }

 
     if (*pexpr_ptr)
         av_expr_free(*pexpr_ptr);
     *pexpr_ptr = new_pexpr;
     av_freep(expr_ptr);
     *expr_ptr = new_expr;
 

     return 0;
 }
 

 static av_cold int init(AVFilterContext *ctx)

 {
     HueContext *hue = ctx->priv;
     int ret;
 

     if (hue->hue_expr && hue->hue_deg_expr) {
         av_log(ctx, AV_LOG_ERROR,
                "H and h options are incompatible and cannot be specified "
                "at the same time\n");
         return AVERROR(EINVAL);
     }
 

 #define SET_EXPR(expr, option)                                          \
     if (hue->expr##_expr) do {                                          \

         ret = set_expr(&hue->expr##_pexpr, &hue->expr##_expr,           \
                        hue->expr##_expr, option, ctx);                  \

         if (ret < 0)                                                    \
             return ret;                                                 \
     } while (0)

     SET_EXPR(brightness, "b");

     SET_EXPR(saturation, "s");
     SET_EXPR(hue_deg,    "h");
     SET_EXPR(hue,        "H");

 #undef SET_EXPR

 
     av_log(ctx, AV_LOG_VERBOSE,

            "H_expr:%s h_deg_expr:%s s_expr:%s b_expr:%s\n",
            hue->hue_expr, hue->hue_deg_expr, hue->saturation_expr, hue->brightness_expr);

     compute_sin_and_cos(hue);

     hue->is_first = 1;

     return 0;
 }
 

 static av_cold void uninit(AVFilterContext *ctx)
 {
     HueContext *hue = ctx->priv;
 

     av_expr_free(hue->brightness_pexpr);

     av_expr_free(hue->hue_deg_pexpr);
     av_expr_free(hue->hue_pexpr);
     av_expr_free(hue->saturation_pexpr);

 }
 

 static int query_formats(AVFilterContext *ctx)
 {

     static const enum AVPixelFormat pix_fmts[] = {
         AV_PIX_FMT_YUV444P,      AV_PIX_FMT_YUV422P,
         AV_PIX_FMT_YUV420P,      AV_PIX_FMT_YUV411P,
         AV_PIX_FMT_YUV410P,      AV_PIX_FMT_YUV440P,

         AV_PIX_FMT_YUVA444P,     AV_PIX_FMT_YUVA422P,

         AV_PIX_FMT_YUVA420P,
         AV_PIX_FMT_NONE

     };

     AVFilterFormats *fmts_list = ff_make_format_list(pix_fmts);
     if (!fmts_list)
         return AVERROR(ENOMEM);
     return ff_set_common_formats(ctx, fmts_list);

 }
 
 static int config_props(AVFilterLink *inlink)
 {
     HueContext *hue = inlink->dst->priv;

     const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);

 
     hue->hsub = desc->log2_chroma_w;
     hue->vsub = desc->log2_chroma_h;

 
     hue->var_values[VAR_N]  = 0;
     hue->var_values[VAR_TB] = av_q2d(inlink->time_base);
     hue->var_values[VAR_R]  = inlink->frame_rate.num == 0 || inlink->frame_rate.den == 0 ?
         NAN : av_q2d(inlink->frame_rate);

 
     return 0;
 }
 

 static void apply_luma_lut(HueContext *s,
                            uint8_t *ldst, const int dst_linesize,
                            uint8_t *lsrc, const int src_linesize,
                            int w, int h)
 {
     int i;
 
     while (h--) {
         for (i = 0; i < w; i++)
             ldst[i] = s->lut_l[lsrc[i]];
 
         lsrc += src_linesize;
         ldst += dst_linesize;
     }
 }
 

 static void apply_lut(HueContext *s,
                       uint8_t *udst, uint8_t *vdst, const int dst_linesize,
                       uint8_t *usrc, uint8_t *vsrc, const int src_linesize,
                       int w, int h)

 {
     int i;
 
     while (h--) {
         for (i = 0; i < w; i++) {

             const int u = usrc[i];
             const int v = vsrc[i];

             udst[i] = s->lut_u[u][v];
             vdst[i] = s->lut_v[u][v];

         }
 
         usrc += src_linesize;
         vsrc += src_linesize;
         udst += dst_linesize;
         vdst += dst_linesize;
     }
 }
 

 #define TS2D(ts) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts))
 #define TS2T(ts, tb) ((ts) == AV_NOPTS_VALUE ? NAN : (double)(ts) * av_q2d(tb))
 

 static int filter_frame(AVFilterLink *inlink, AVFrame *inpic)

 {
     HueContext *hue = inlink->dst->priv;
     AVFilterLink *outlink = inlink->dst->outputs[0];

     AVFrame *outpic;

     const int32_t old_hue_sin = hue->hue_sin, old_hue_cos = hue->hue_cos;

     const float old_brightness = hue->brightness;

     int direct = 0;

     if (av_frame_is_writable(inpic)) {
         direct = 1;
         outpic = inpic;
     } else {

         outpic = ff_get_video_buffer(outlink, outlink->w, outlink->h);
         if (!outpic) {
             av_frame_free(&inpic);
             return AVERROR(ENOMEM);
         }
         av_frame_copy_props(outpic, inpic);

     }

     hue->var_values[VAR_N]   = inlink->frame_count_out;

     hue->var_values[VAR_T]   = TS2T(inpic->pts, inlink->time_base);
     hue->var_values[VAR_PTS] = TS2D(inpic->pts);
 
     if (hue->saturation_expr) {
         hue->saturation = av_expr_eval(hue->saturation_pexpr, hue->var_values, NULL);

         if (hue->saturation < SAT_MIN_VAL || hue->saturation > SAT_MAX_VAL) {
             hue->saturation = av_clip(hue->saturation, SAT_MIN_VAL, SAT_MAX_VAL);
             av_log(inlink->dst, AV_LOG_WARNING,
                    "Saturation value not in range [%d,%d]: clipping value to %0.1f\n",
                    SAT_MIN_VAL, SAT_MAX_VAL, hue->saturation);

         }

     }

     if (hue->brightness_expr) {
         hue->brightness = av_expr_eval(hue->brightness_pexpr, hue->var_values, NULL);
 
         if (hue->brightness < -10 || hue->brightness > 10) {
             hue->brightness = av_clipf(hue->brightness, -10, 10);
             av_log(inlink->dst, AV_LOG_WARNING,
                    "Brightness value not in range [%d,%d]: clipping value to %0.1f\n",
                    -10, 10, hue->brightness);
         }
     }
 

     if (hue->hue_deg_expr) {
         hue->hue_deg = av_expr_eval(hue->hue_deg_pexpr, hue->var_values, NULL);
         hue->hue = hue->hue_deg * M_PI / 180;
     } else if (hue->hue_expr) {
         hue->hue = av_expr_eval(hue->hue_pexpr, hue->var_values, NULL);

         hue->hue_deg = hue->hue * 180 / M_PI;

     }
 
     av_log(inlink->dst, AV_LOG_DEBUG,

            "H:%0.1f*PI h:%0.1f s:%0.1f b:%0.f t:%0.1f n:%d\n",

            hue->hue/M_PI, hue->hue_deg, hue->saturation, hue->brightness,

            hue->var_values[VAR_T], (int)hue->var_values[VAR_N]);

     compute_sin_and_cos(hue);

     if (hue->is_first || (old_hue_sin != hue->hue_sin || old_hue_cos != hue->hue_cos))

         create_chrominance_lut(hue, hue->hue_cos, hue->hue_sin);

     if (hue->is_first || (old_brightness != hue->brightness && hue->brightness))

         create_luma_lut(hue);
 

     if (!direct) {

         if (!hue->brightness)
             av_image_copy_plane(outpic->data[0], outpic->linesize[0],
                                 inpic->data[0],  inpic->linesize[0],
                                 inlink->w, inlink->h);

         if (inpic->data[3])
             av_image_copy_plane(outpic->data[3], outpic->linesize[3],
                                 inpic->data[3],  inpic->linesize[3],
                                 inlink->w, inlink->h);
     }

     apply_lut(hue, outpic->data[1], outpic->data[2], outpic->linesize[1],
               inpic->data[1],  inpic->data[2],  inpic->linesize[1],

               AV_CEIL_RSHIFT(inlink->w, hue->hsub),
               AV_CEIL_RSHIFT(inlink->h, hue->vsub));

     if (hue->brightness)
         apply_luma_lut(hue, outpic->data[0], outpic->linesize[0],
                        inpic->data[0], inpic->linesize[0], inlink->w, inlink->h);

     if (!direct)

         av_frame_free(&inpic);

 
     hue->is_first = 0;

     return ff_filter_frame(outlink, outpic);

 }
 

 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
                            char *res, int res_len, int flags)
 {

     HueContext *hue = ctx->priv;

     int ret;

 #define SET_EXPR(expr, option)                                          \
     do {                                                                \
         ret = set_expr(&hue->expr##_pexpr, &hue->expr##_expr,           \
                        args, option, ctx);                              \
         if (ret < 0)                                                    \
             return ret;                                                 \
     } while (0)

     if (!strcmp(cmd, "h")) {
         SET_EXPR(hue_deg, "h");
         av_freep(&hue->hue_expr);
     } else if (!strcmp(cmd, "H")) {
         SET_EXPR(hue, "H");
         av_freep(&hue->hue_deg_expr);
     } else if (!strcmp(cmd, "s")) {
         SET_EXPR(saturation, "s");

     } else if (!strcmp(cmd, "b")) {
         SET_EXPR(brightness, "b");

     } else
         return AVERROR(ENOSYS);
 
     return 0;

 }
 

 static const AVFilterPad hue_inputs[] = {
     {
         .name         = "default",
         .type         = AVMEDIA_TYPE_VIDEO,

         .filter_frame = filter_frame,

         .config_props = config_props,
     },
     { NULL }
 };
 
 static const AVFilterPad hue_outputs[] = {
     {
         .name = "default",
         .type = AVMEDIA_TYPE_VIDEO,
     },
     { NULL }
 };
 

 AVFilter ff_vf_hue = {

     .name            = "hue",
     .description     = NULL_IF_CONFIG_SMALL("Adjust the hue and saturation of the input video."),
     .priv_size       = sizeof(HueContext),
     .init            = init,
     .uninit          = uninit,
     .query_formats   = query_formats,

     .process_command = process_command,

     .inputs          = hue_inputs,
     .outputs         = hue_outputs,
     .priv_class      = &hue_class,

     .flags           = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,

 };